4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Petr Pavlu <petr.pavlu@xxxxxxxx>
[ Upstream commit 14a20e5b4ad998793c5f43b0330d9e1388446cf3 ]
The net.ipv6.route.flush system parameter takes a value which specifies
a delay used during the flush operation for aging exception routes. The
written value is however not used in the currently requested flush and
instead utilized only in the next one.
A problem is that ipv6_sysctl_rtcache_flush() first reads the old value
of net->ipv6.sysctl.flush_delay into a local delay variable and then
calls proc_dointvec() which actually updates the sysctl based on the
provided input.
Fix the problem by switching the order of the two operations.
Fixes: 4990509f19e8 ("[NETNS][IPV6]: Make sysctls route per namespace.")
Signed-off-by: Petr Pavlu <petr.pavlu@xxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240607112828.30285-1-petr.pavlu@xxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/route.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5170,12 +5170,12 @@ int ipv6_sysctl_rtcache_flush(struct ctl
if (!write)
return -EINVAL;
- net = (struct net *)ctl->extra1;
- delay = net->ipv6.sysctl.flush_delay;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (ret)
return ret;
+ net = (struct net *)ctl->extra1;
+ delay = net->ipv6.sysctl.flush_delay;
fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
return 0;
}
